Refrigeration apparatus



March 5, 1929. e. M. TROUP REFRIGERATiON APPARATUS Filed Oct. 17, 1927 3 a Z. VI

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Patented Mar. 5, 1929 UNITED STATES PATENT F GEORGE u. amour, or DAYTON, OHIO, ASSIGNOR, BY MESNE AssIcNMENrs, ro'rnIGInma conrona'rIoN, A CORPORATION or DELAWARE.

aErnIemrIoN arrmrus.

Application flied October 17, 1927. serial No. 226,686.

The present invention relates to improve ments in refrigerating apparatus of the mechanically operated type in which a com-- pressor-expander type of circuit is used for effecting refrigeration in a cooling unit.

It is an object of the invention to provide an improved means for operating a plurality of such units simultaneously with one compressor and for permitting the operation of said units at selective temperatures.

It is another objectof the invention to provide improved means for controlling the supply of refrigerant to each unit independently of the others in response tothe temperature there prevailing.

It is a further object of the invention to provide a common return conduit for the refrigerant of all of the units of a refrigerating system in which the flow of refrigerant is controlled by the pressure within the units and to provide means responsive to the pressure in such conduit for controlling there frigerant circulating mechanism.

' Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the present invention is clearly ShOWIl. l I i 1 In the drawings: Fig. 1 shows a diagrammatic view of the improved refrigerating system of the inven- Fig. 2 is a view in cross section of a control device used in the system for governing the operation of the units; and

Fig. 3 shows an expansion valve used 1n the system for producing the refrigeration in the various units. .In the mechanical type refrigerator the flow of refrigerant is preferably effected by means of a compressor-expander type of mechanism wherein'a suitable refrigerant is forced by a pumping mechanism through an expansion valve or the like, into a loop -of pipes or the like, generally termed a n evaporator, which latter is termed, the cooling umt or refrigerating element. 1 t

' When a plurality of such units or elements are operated fromone compressor, it may be desirable .tocontr 1 the operating temperatures in the individual units in such a man-' nerthat it be possible to control the temperatures of the units independently of 'one another, for example it may be desirable In accordance with the present invention means are provided for controlling the flowof refrigerant to each unit in response to thecondition ofthe unit and more particularly to the temperature of the unit. A common return circuit is provided for all of the units and means are associated with such circuit for controlling the refrigerant circulating mechanism. v

Referring in detail to the drawings, the refrigerating system to which the invention 1s applled by way of illustration com rises a compressor 10 driven by a motor 11 t rough a belt 12. The compressor forces gaseous refrigerant through pipe'13'into the condenser 14 where it is cooled and from which is passes by way of pipe branches 15 and 16 to the expansion valves 17 and 18 which allow it to issue under pressure through narrow orifices into the'evaporators 19 and 20. These evap- The operation of each expansionvalve is controlled by means of devices" 24 and 25..

which are responsiveto the temperatures prevailing in the compartments 21, 22 cooled by the evaporators 19, 20. Each of these temperature responsive devices may beset if desired, for difi'erent temperatures so'that the chamber 21 for example, may be maintained at a 'diflerent temperature from chamber 22.

Fig. 2 shows one of the temperature re- I 'sponsive devices 24 and 25 in detail. The device comprises essentially a metallic casing 26 provided with means such as threads 46 for attachment to the interior of compartments 21 and 22 and containing a valve 2'? bearing against valve seat. 28 for controlling or 'obstructingthe flow of fluid between passages 29 and 30. The head of valve 27 is carried by a flexible bod 31 such as ametallic bellows preferably of t e typejknown in the trade as a sylphon. This body may be filled .with a fluid readily responsive to chan es in temperature. Itis obvious that the 'tion and contraction of the bellows 31 will operate the valve head 27 and hence control the flow of fluid from passage 29 through passage 30.

The valve may be calibrated by screwing the head 27 more or less into the threaded bushin 32 on the head of the sylphon.

he expansion valve shown in Fig. 3 as an illustrative executional example of one portion of the a paratus of the invention may be of any suita le t p'e.

In the valve s own, liquid refrigerant enters at 33 and passes into the chamber 34 whence it leaves, by pipe connection 35, its. passage from 33 to 35 being controlled by a needle valve 36. The operation of needle valve 36 is controlled by a diaphragm 37.

The needle. valve is carried on a yoke 38 shown in cross section which is attached to the'center of the diaphragm and which latter in turn is secured at its edges to the casing and thus forms one wall of the chamber. A rod 39 is attached to the diaphragm and to the yoke so as to form a rigid structure with the yoke and the needle valve. This rod is urged to theeri ht as shown in the drawing to close the va ve 36 through intermediary.

of a sprin 40 which is compressed between an adjusta le nut 41 and shoulder 42. Thechamber 43 and therefore the side of the diaphragm'facing it is exposed to the influence of atmospheric air and the diaphragm is moved to the left to open the valve against the force of the spring 40 whenever a reduction of pressure occurs in the chamber 34.

The operation of the system is as follows:

The expansion valve shown in detail in Fi 3 and diagrammatically indicated by 17 an 18 in Fig. 1 is arranged to maintain a constant pressure in the evaporator or cooling unit 19, one of the several units being selected fordiscussion of the operating principle. The flow'of fluid to the expansion valve 18 is controlled by the sylphon operated temerature-responsive device shown in detail in ig 2 and diagrammatically indicated by 24 in ig. 1. Thls valve is placed inthe compartment 21 so as to be directly affected by g the temperature conditions there prevailing.

As the temperature of the compartment 1ncreases' the temperature and likewise the pressure in the evaporator 19 will increase and by the time that this pressure attains a 0'5 may becooled sufficiently so that 24 is closed, refrigerant ex predetermined value the bellows 45 will have expanded 'sufliciently to actuate the switch to close the motor circuit thus starting the compressing cycle. The setting or calibration of control valve 24 is such that it will 0 11 prior to the starting ofthe motor. The ow of refri gerant to the eva orator is controlled primarily by the expanslon valve '18. However, when a predetermined low temperature is attamed in the chamber 21 valve 24 will.

operate to obstruct the flow of refrigerant to the cooling unit 19. Although chamber 21 there may still exist a demand for refrigeration in compartment 22 so that the compressor will continue to operate to withdraw refrigerant from the cooling unit 20, and when the temperature of compartment 22 attains a predetermined selected low value the valve 25 will close to obstruct the flow of refrigerant to the cooling unit 20. After all of the control devices 25 and 24 have operated to bbstruct the flow of refrigerant to the respetcive units, the, pressure within the units and in the pipe 23 will decrease quickly and this sudden decrease in pressure will actuate rupt the motor circuit. It is of courseunderstood that the pressure at which the swltch the switch 44 through the bellows 45 to inter- 44 operates to stop the motor is considerably lower than the normal operating pressures within the cooling units. I

The system shown therefore provides a means for operating a plurality of separate refrigerating elements simultaneously from one refrigerant circulating means with provision for.operat ing each unit at a selective temperature, and controlling the apparatusby means of one switch operated by low pressure prevailing in a return conduit common to all of the refrigeratingelements.

While the form of embodiment of the invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms. might be adopted, all coming within the scope of the claims which follow.

Whatis claimed is as follows:

1. Refrigeratin apparatus including in combination a re rigerating element, means for circulating a refrigerating medium.

through said refrigerating element, means responsive to the pressure of the refrigerating medium in the elementfor controlling v the supply of medium thereto and means responsive to the temperature of said element for controlling the supply of refrigerating medium thereto and means responsive to the pressure within the element for controlling thereto in responseto pressure within said J evaporator, a second valve in the refrigerant supply conduit/for controlling the flow of re 'gerant thereto in res onse to the temperature surrounding sai eva orator, and

means for controlling said circu ating means in response to the pressure in said exhaust condult.

3. Refrigerating apparatus comprising a plural ty of evaporators having individual refrigerant. supply conduits and a common aust conduit, a refrigerant circulating device for su plying refrigerant to the thermal condition of said associated to and wlthdrawing re rigerant from said eyaporator, and means responsive to the presl evaporators, means 1n each refrigerant supsure in said common exhaust conduit for conply conduit forpcontrolling the flow of re-' trolling the refrigerant circulating means. 5 frlgerant thereto in response to the pressure In testimony whereof 1 hereto aflixed my in the associated evaporator, means in each signature. refri erant supply conduit for controlling 1 the 50w of refrigerant thereto in response GEORGE M. TROUP. 

